Facebook’s recent implementation of “custom” gender options and gender-neutral pronouns provided transgender and gender-non-conforming users with new ways to represent gender identity online. We analyze user response to and use of these affordances. We found that while many transgender and gender non-conforming Facebook users used and appreciated the new options for gender representation, the system still constrained self-presentation for some. Additionally, use of custom gender options complicated gender identity disclosure for many participants. Results highlight tensions around the ability of classification systems to categorize identities.